unfortunately the battery of our tourer is dead. I couldn`t find a label indicating amp.
What is the sufficient amount of ampere for a 6V T battery?
You need a "Group 1" 6 volt battery. Amp hours is a measurement of how long you can discharge a fully charged battery at 1 amp. Any group 1 battery will fit into the box. You will need to place about 1" board under it, but the other dimensions fit fine.
A std Group 1 6volt automotive lead acid battery is about 670cold crank amps. More than enought for the T. This Group 1 size is about 8 7/8 x 6 7/8 x 8 and fits into the battery bracket.
Don't let them sell you a 19L battery. It's for a Volkswagen, footprint is the same but way shorter. I'm a battery guy. Most group 1 batterys are built the same....but, If you can find a deal on a CAT as in catepillar marked group 1 they are HEAVY DUTY.
Starting batteries should not be discharged beyond 20%, so the available amp-hours is only 20% of the rating. A deep discharge battery can be discharged to 80% of the capacity or 4 times as much for the same rating. Cold crank amps is a measure of how much current is available for starting.
Are you using the battery for starting? If so, get a starting battery. If you are using it only to run the coils and perhaps lights, get a deep discharge battery.
As Scott was saying, different batteries have different quality. Usually the more expensive, and heavier, the battery, the better it is.
Never let a lead-acid battery completely discharge. The lifetime will be severely shortened. Charge a discharged battery as soon as possible and keep a small float voltage on it when in storage.
Follow the safety rules with batteries. They contain an acid. Don't short them. Wear eye protection and rubber gloves. A baking soda solution will neutralize any spills. 4 ounces per quart. Wash with water and dry after the solution. Use a protective grease on the terminals and connectors to keep them in good shape.
The battery is going to be a starter battery.
Here in Germany I use a 50 amp hour battery for my Citroen 2CV of 1957. The car has a tiny flat-twin motor (425ccm!) and a small starter motor compared to the T. I have not tried to start the Lizzie with the Citroen`s battery so far, but I think the T needs a unit with more amp hours.
Norm and Scott:
Is a "Group A battery" a measure of size or also amp hours? I have never heard that term over here, so please excuse my ignorance.
We just don`t want to buy a battery that will allow two starts but fail with the third try.
Bernd, from rainy northern Germany
My 6 Volt Interstate battery lasted 8 years. They cost a little more, about $100. Some people have claimed they did not last at all. The specifications are the same for any 6 volt Group 1 Battery as the size is a standard. These are listed on the Interstate website.
Product ID: 1-VHD (Model T Ford Battery Type)
Cranking Amps: 720
Cold Cranking Amps: 640
Termination: Top Post
Weight: 31 Pounds
Width: 6.88 Inches
Length: 8.88 Inches
Height: 8.75 Inches
You will have to ask someone familiar with the batteries in Germany. The Group 1 is the same used by many of the automobiles in the USA before about 1950 when they began to change to 12 volt batteries. There were also group 2 batteries, but they are bigger and don't fit. They might have named the batteries differently in Germany.
I will find out.
The battery you seek is rather common size that fits Ford model N (2N,9N, 8N) tractors. If they have tractor stores in Germany go there since Ford exported those tractors just about every place on the planet. Don't worry about the AMPS just get a 6V battery that fits rather snugly into that holder under the T frame and the battery will have plenty of current to start the T. The Model T is a low compression 4 cylinder motor and just about any 6V battery designed for an auto or tractor with at least a 4 cylinder engine will probably work fine. Repair the charging system and make sure that it works because any size battery is going to have problems if the charging system is dead or malfunctioning.
Manufacturers build their batteries to an internationally adopted Battery Council International (BCI) group number (24, 34, 35, 65, 75, 78, etc.). These specifications, which are based on the physical case size, terminal placement, type and polarity is used primarily in North America. In Europe, the EN, IKC, Italian CEI, and German DIN standards are used:
BS EN 50342:2001 Lead-acid starter batteries. General requirements, methods of test and numbering
BS EN 60095-2:1993 Lead-acid starter batteries. Dimensions of batteries and dimensions and marking of terminal
Feature on 6 volt battery in early autos
BCI Group sizes, scroll to the Group 1
So see if your local automotive battery dealer can find you a 'BCI Group 1 size 6 volt lead acid battery, that will be the right one for the T.